Abstract: The present invention discloses a method for assessment of previous ethanol exposure comprising the steps of: (i) obtaining a sample from the body of a subject; (ii) quantitatively determining the level of one or several bio-precursors of PEth (Formula I) and the level of the corresponding one or several PEth-homologues (Formula II) in the sample; and (iii) obtaining a ratio between the level of one or several bio-precursors of PEth and the level of the corresponding one or several PEth-homologues; wherein the subject is a human or animal. Additional related methods are also disclosed.